Process of making pearl buttons.



No. 863,498. PATENTED wefls, 1907.

N. BARR 'JB.

PROCESS OF MAKING PEARL BUTTONS.

APPLICATION PILED mm. a, 1900.

UNITEI) STATES PATENT OFFICE.

NICHOLAS BARRY, JR.,

OF MUSGATINE, IOWA.

PROCESS OF MAKING PEARL BUTTONS.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed December 3,1906. Serial No. 346,135.

' ture of so-called pearl buttons from the mussel shells found in the Mississippi river and tributaries thereof and from which large quantities of buttons are now being manufactured. These mussel shells have a very fine interior pearl portion which gradually thickens from the tip or web of the shell to the butt or knuckle portion thereof, and the interior of the shell has a very fine pearl surface and is roughly spherically concave in contour. The outer portion of these shells is rough and gradually thickens from the ,tips or edges of the shell to the hinge and ridge portions thereof. The hinge and ridge portions of said shells are so thick and hard that they cannot by any of the present known processes of manufactiu'e be economically worked because the blanks must be cut from the shell by tubular saws and the hinge and ridge portions are too thick to be practicably cut by the saws, and even if they were cut the blanks resulting therefrom would be useless as they would have crooked faces and be longer than their diameters and would be practically cylinders which could not be split into proper thickness for buttons because of the peculiar pearl formation of the shell, the pearl itself practically forming a series of layers ending in a close spiral formation in the hinge or butt portions of the shell. Therefore by the present known methods of cutting, only a portion of the shell outside of the hinge and ridge portions is capable of being utilized, and, further, the blanks cut from the shells adjacent the ridge portions are lop-sided or what is technically termed mule-hoof blanks, because the blanks out are thicker at one side than on the other on account of the natural formation of the shell and when ground down to a thickness, the two opposite edges of the button will be slanted in the same direction, making an imperfect button resembling in contour the mule hoof. Furthermore, by the present known methods of manufacture, it is necessary to cut blanks out of the shell by successive operations of the tubular cutter or saw, the shell being held by the operator and then advanced toward the saw to cut a blank, after which cutting operation the shell must be repositioned to permit of the next cutting operation being performed.

The objects of my present invention are, first, to

enable the entire shell to be utilized so that blanks can be cut from the hinge or ridge portions thereof, whereby I gain an increase of about forty per cent. in buttons from the shells over what has been heretofore possible by the present known processes; second, to enable a plurality of blanks to be cut from the shell at one 0poration, which has been impossible by any of the present known methods, because of the irregularity 10f the shell; third, to reduce the shell to approxilmately uniform thickness, thereby facilitating the blank-cutting operations and enhancing the value of the resulting product and lessening the cost of subsequently reducing the blanks to proper thickness and mately parallel with the inner surface thereof, and as a result the prepared shell as a whole is concavo-convex and approximately resembles the segment of a hollow sphere. The next step in my process is to take such prepared shells and place them one at a time upon a support whose outer surface is convex and substantially conforms to the internal concave surface of the shell so as to form a firm support therefor. Then,

' while the shell is so supported, I subject it to the action of cutters operating upon the shell, preferably from the back or convex side thereof, instead of from the inner or concave side thereof as is now customarily done. By this mode of cutting the blanks the shell is less liable to fracture under pressure of the cutters, because the pearl formation in the shell is such that the inner layer is hardest and largest while each suc-' cessive outer layer is smaller, and thus by working from the back of the shell inward, the shell has a firm support and is not liable to be split or fractured under pressure of the cutter, as it would be if the cutter were operating from the inner side of the shell. Furthermore, by operating against the outer convex side of the shell I am able to employ a plurality of blankcutters operating simultaneously upon the shell and can at one operation, if desired, cut all the blanks from the shell that it will afford. For this purpose l prefer to use the machine shown in my application filed December 3, 1906, Serial No. 346,134.

The invention therefore consists in the novel method above outlined, of treating the shells preparatory to cutting, and the manner of cutting the blanks therefrom as hereinafter set forth in the claims, and to facilitate the understanding of the invention, I will briefly describe the process in detail with reference to the accompanying diagrammatical drawings, which will impart a clear understanding thereof, and then refer to the claims for the summaries of the invention and for concise statements of that for which protection is desired.

In the drawingsFigure 1 is a view of an ordinary mussel-shell before cutting; Fig. 2 is a longitudinal section through the shell on line 22, Fig. 1, showing its internal configuration; Fig. 3 is a longitudinal section through the same shell after being ground; Fig. 4 is a transverse section on line 4-4 of Fig. 3; Fig. 5 is a diagrammatical view illustrating the manner of supporting the shell preparatory to cutting the blanks therefrom; Fig. 6 is a view of a prepared shell after it has been cut; Fig. 7 is a view of one of the blanks produced from the prepared shell.

The shell S has a very heavy hinge or butt portion s, at the point where the shells are hinged together and extending from this hinge portion at the rear of the shell, is a thickened or ridge portion 8. The web portion 5 of the shell is the only portion that can be cut by the present known methods, the hinge portion 8 and the ridge portion s not being considered workable and being thrown away. The Web portion a is concave on its inner surface, but is of irregular thickness because the shell externally increases in thickness from the periphery of the web portion 8 back to the hinge and ridge portions so that the blanks cut from such shells along the lines indicated by the circles in Fig. 1 will be of varying thickness and the blanks cut from the openings 1 will be hoof-shaped or bevel-sided, and a perfect button-cannot be made therefrom.

In carrying out my process, I preferably grind the shells internally to reduce the interior parts of the hinge s and the ridge .9 to approximately the same plane as the inner portion of the web 3 grinding the shell by a convex-surfaced grinder so as to remove the portion 1' below the line A, Fig. 2. I then preferably grind the exterior of the shell along the line B, Fig. 2, removing the exterior portion 7 above the said line by means of a concave-surfaced grinding wheel, preferably using the grinding mechanism shown in my application filed De cember 3, 1906, Serial No. 346,174. After passing through such grinders, the shell is reduced to practically the form illustrated in Figs. 3 and 4, being concavoconvex and approximately the segment of a hollow sphere. I then take such prepared shells and place them with their concave or pearl-faced side downward upon a shell-support, shown at C in Fig. 5, which has a convex outer surface substantially conforming to the inner concave surface of the shell. This support may be constructed and operated as described in my application for patent Serial No. 346,134. While thus supported the shell is subjected to the action of tubular saws, preferably a series of said saws operating simultaneously, as indicated at D, Fig. 5, each saw being arranged substantially perpendicular to a tangent at the portion of the surface of the shell on which it operates and is adapted to move toward or from the convex surface of the shell to cut blanks therefrom. Preferably I employ a sufficient number of such cutters, operating synchronously, to cut all the blanks from the shell at one operation. As indicated in Fig. 6 ten cutters have been employed to simultaneously cut a corresponding number of blanks from the shell. By having these outters operate against the outer or convex side of the shell, they are not liable to fracture or split the shell by pressure thereon, and, furthermore, as the shell is supported solidly by the convex head C it is not subjected to any rupturing strain.

By this method of first preparing the shell in concavoconvex form and then supporting it upon a correspondingly shaped head and then cutting the blanks therefrom simultaneously by means of cutters advanced against the convex outer or back side of the shell, it will be seen that I utilize the entire shell, including the hinge and ridge portions, and thereby gain a large increase of product and a better product, in that the pearl in the ridge and hinge portions is thicker and harder than at any other part of the shell and, furthermore,

all the blanks cut from my prepared shell will have parallel sides and be straight-edged, as indicated in Fig.

7, so that perfect buttons can be produced therefrom, Iand no unequal or mule hoof blanks will be produced, and less subsequent work is required to perfect -the buttons produced fronithe blanks cut by my process, and I greatly lessen the labor required in producing the blanks and can perform the operation of cutting a number of blanks simultaneously from the shell as set forth in my application Serial No. 346,134 aforesaid.

I-Ieretofore it has not been practical to cut the rough shells and get first class blanks from the thicker parts, particularly with crooked or ridged shells, and the majority of such shells have a protruding swell or ridge on the face-portion as indicated at s in Fig. 1, which has to be avoided in the present known methods of cutting and consequently further lessens the number of blanks obtainable from such a shell, as the blanks cut from such portion would be humped or grooved on their faces, and inclined or beveled on their backs, being thus defective on both faces and edges; on the other hand the blanks cut from the thicker parts of the shell, even when smooth surfaced on the pearl or inner side, are beveled on their edges andproduce what are called mule foot buttons, It is also not practical to cut from the back of the shell, for the same reason; as the thick portion of the shell is beveled or wedge-shaped, and the saws would be injured by striking at one side first, and the blanks would be mule-hoof in shape, resulting in imperfect buttons.

By first grinding the shells concavo-convex as described, I substantially remove all high and uneven surfaces from the face and all surplus material from the back, making it substantially conform to the ground face, thereby putting the shells in such condition that it is easy for the workman to cut the blanks therefrom by hand, or to cut a number of blanks therefrom simultaneously by automatic mechanism; and such shells yield fine blanks from hitherto unused waste parts of the shell. l

In short by this invention I am able to utilize the hitherto unused portions of shells, and obtain a greater number of blanks from a given size shell than it has been possible to obtain by the present known methods. I also obtain a more uniform quality of blanks, thus requiring less after treatment to make them into buttons, and I am able to cut one or all the blanks simultaneously from the shell at one operation, thereby lessening the work and labor heretofore required to produc blanks from these shells.

Having described my invention what I claim as new and desire to secure by Letters Patent is 1. The herein described method of making pearl button blanks consisting in reducing the shell to concavo-convex form approximating the interior contour of the shell and of substantially uniform thickness, and then cutting blanks from the shell.

2. The herein described method of making pearl button blanks consisting in reducing the shell to a concavo-convex form approximating the interior contour of the shell; placing said shell upon a support substantially conforming to its inner concave surface and then cutting blanks therefrom by directing the cutter against the outer or convex side of the shell.

3. The herein described method of making pearl button blanks consisting in reducing the shell to concavo-convex form and to a substantially uniform thickness, and then supporting the shell on its concave surface and simuland ridge portions having been removed, substantially as 30 described.

In testimony that I claim the foregoing as my own, I affix my signature in presence of two Witnesses.

NICHOLAS BARRY, JR. Witnesses 'ILLIAM R. .Ln'xn, ARTHUR E. DOWELL. 

